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STEREOTACTIC BODY RADIATION THERAPY Presented at the Annual Meeting of the

STEREOTACTIC BODY RADIATION THERAPY Presented at the Annual Meeting of the American College of Medical Physics in Orlando, Florida, May 24, 2005. STEREOTACTIC BODY RADIATION THERAPY(SBRT ). Part 1: Overview of SBRT (S.H. Benedict, Virginia Commonwealth University)

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STEREOTACTIC BODY RADIATION THERAPY Presented at the Annual Meeting of the

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  1. STEREOTACTIC BODY RADIATION THERAPY Presented at the Annual Meeting of the American College of Medical Physics in Orlando, Florida, May 24, 2005

  2. STEREOTACTIC BODY RADIATION THERAPY(SBRT) Part 1: Overview of SBRT (S.H. Benedict, Virginia Commonwealth University) • AAPM Task Group 101: SBRT • ASTRO Guidelines Part 2: Treatments of the spine with SBRT (Paul Medin, Ph.D., UCLA) Part 3: SBRT in the “Conventional” Clinical Setting Bill Hinson, PhD, Wake Forest University Part 4:KV and MV imaging in SBRT Michael lovelock, PhD, MSKCC

  3. EXTRACRANIAL STEREOTACTICRADIOSURGERY – What’s in a name? • ESRT is the use of external beams to treat lesions of the body with “surgical” doses and high precision tumor identification and relocalization employing “stereotactic” image guidance or implanted fiducials. • Extracranial stereotactic …. Radioablation / Radiosurgery / Radiotherapy • Surgery vs. Ablation vs. Therapy vs. … • According to the chief CPT code developer it will be called: Stereotactic Body Radiotherapy

  4. SBRT REQUIRES: • Higher confidence in tumor targeting • Reliable mechanisms for generating focused, sharply delineated dose distributions • Reliable accurate patient positioning accounting for target motion related to time dependent organ movement

  5. SBRT: why try it? • Highly efficient and extremely potent form of radiation treatment applicable to a wide variety of tumor types • Safe and effective for patients with medically inoperable primary lung cancer • Timmerman R, et al. Chest, 2003. • Ongoing investigations for patients with primary liver cancer (hepatocellular carcinoma) • Extremely common type of cancer worldwide • These patients are often unfit for surgery • Non-invasive alternative to surgery, RFA, or cryosurgery for selected patients with “oligometastases” • Especially relevant in era of improving systemic “targeted therapy” * Slide courtesy of Brian Kavanagh / University of Colorado

  6. SBRT: what is it? • Stereotactically localized, ultra-high-dose radiotherapy delivered to discrete tumor nodules in the lung, liver, and other extracranial locations in a hypofractionated regimen (typically 1-5 treatments) • The goal is complete cancer cell kill within the treated volume • Beginning in January, 2005, SBRT will be a category III CPT code for billing purposes * Slide courtesy of Brian Kavanagh / University of Colorado

  7. SBRT: who started it? • Answer:Blomgren and Lax, Karolinska Institute, Stockholm, Sweden * Slide courtesy of Brian Kavanagh / University of Colorado

  8. SBRT: who started it? * Slide courtesy of Brian Kavanagh / University of Colorado

  9. Conventional vs SBRT * Slide courtesy of Brian Kavanagh / University of Colorado

  10. Linear Accelerators with features especially suitable for SBRT * Slide courtesy of Brian Kavanagh / University of Colorado

  11. SBRT : Immobilization/Repositioning * Slide courtesy of Brian Kavanagh / University of Colorado

  12. SBRT: how much is enough? Fowler JF, Tome WA, Welsh JS. Estimation of the Required Doses in Stereotactic Body Radiation Therapy. In Stereotactic Body Radiation Therapy, Kavanagh BD and Timmerman RD, eds. Lippincott Williams & Wilkins, 2005. * Slide courtesy of Brian Kavanagh / University of Colorado

  13. Fowler JF, Tome WA, Welsh JS. Estimation of the Required Doses in Stereotactic Body Radiation Therapy. In Stereotactic Body Radiation Therapy, Kavanagh BD and Timmerman RD, eds. Lippincott Williams & Wilkins, 2005. * Slide courtesy of Brian Kavanagh / University of Colorado

  14. AAPM Task Group 101:Stereotactic Body Radiation Therapy • The AAPM RTC approved the following charges of the task group: • Charge (1): To review the literature and identify the range of historical experiences, reported clinical findings and expected outcomes • Charge (2): To review the relevant commercial products and associated clinical findings for an assessment of system capabilities, technology limitations, and patient related expectations and outcomes. • Charge (3): Determine required criteria for setting-up and establishing an ESRT facility, including protocols, equipment, resources, and QA procedures. • Charge (4): Develop consistent documentation for prescribing, reporting, and recording ESRT treatment delivery.

  15. AAPM TG 101: SBRT - Table of Contents:1. . Clinical Rationale for SBRT 2. Review of Clinical History and Current Use of SBRT (Volker Steiber)3. Patient Immobilization, Relocalization, and Verification 4a. Treatment Planning and Dosimetry 4b. Treatment plan evaluation and dose reporting 5. Dosimetry 6. SBRT Treatment Delivery Technology 7. Clinical Implementation of SBRT8. Future directions

  16. RADIATION THERAPY ONCOLOGY GROUP (RTOG) 0236:A Phase II Trial of Stereotactic Body Radiation Therapy (SBRT) in the Treatment of Patients with Medically Inoperable Stage I/II Non-Small Cell Lung Cancer • PI: Robert Timmerman, MD • Eligilibity • Patients with T1, T2 (≤ 5 cm), T3 (≤ 5 cm), N0, M0 medically inoperable non-small cell lung cancer; • Patients with T3 tumors chest wall primary tumors only • No patients with tumors of any T-stage in the zone of the proximal bronchial tree*. • SBRT dose: 20 Gy x 3 fractions

  17. RADIATION THERAPY ONCOLOGY GROUP (RTOG) 0236:Dosimetry specifications • “Zone of the proximal bronchial tree” (figure) • Target dose homogeneity limits • Dose “isotropicity” limitation requiring falloff of approx 50% within 2 cm of PTV • V20 < 10% • Spinal cord, heart, esophagus, etc. limits

  18. SBRT PHYSICS AND TECHNOLOGY • 1. CT simulation: Assess tumor motion • 2. Immobilization: Minimize motion, breathing effects • 3. Planning: Small field dosimetry considerations • 4. Repositioning: High precision patient set-up: Fiducial systems, IR/LED Active and Passive markers, US, Video • 5. Relocalization: Identify tumor location in the treatment field: * MV/ KV Xray, Implanted markers and/or set-up fiducials * Motion tracking and gating systems * Real-time tumor tracking systems with implanted markers • 6. Treatment delivery techniques • Adapted conventional systems • Specialized SRT: Novalis, Cyberknife, Trilogy

  19. Clinical Implementation of ESRT – “These techniques are unusual in the high technology realm of radiation treatment in that they require more specialized training of physicians and physicists rather than specialized equipment.” * Timmerman et al, Technology in Cancer Research and Treatment – 2003

  20. SUMMARY: Technical elements of QA • The physicist should be responsible for all technical QA procedures: • Imaging equipment • Localization and simulation equipment • Treatment planning and evaluation system • Treatment delivery equipment • Treatment verification equipment

  21. SUMMARY: Clinical elements of SBRT QA • A physician and physicist should carry out all clinical QA procedures: • Consistent target volume and organs–at–risk delineation • Quantitative assessment of target and organ motion during imaging and treatment • Quantitative assessment of setup variation during imaging and treatment • Patient–specific QA NEED TO ESTABLISH TERMINOLOGY AND REPORTING CONVENTIONS • Prescription considerations: GTV, margins, dose inhomogeneity/uniformity • Biological evaluations: EUD, NTCP, etc • Dose and Fractionation strategy: (1 to 5 fractions, QOD, QD, etc) next

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